Because Canadian humane transport laws are vague and rarely enforced, many trailers are overloaded so the hauler can maximize profit.

Overcrowding is directly linked with a higher rate of falling and suffocation. This is because animals have a higher centre of gravity and must have all 4 feet on the ground to be able to remain standing.

During winter, overcrowded animals are forced to have their bodies pressed up against the metal sides of the trailers where they sustain frostbite to flesh exposed through the port holes. Still-lactating sows may even freeze to the sides of trailers when overloaded and unable to escape the sides.

During summer, overloading causes heat stroke as temperatures quickly reach 40C to 50C, particularly when the trailer is standing still (as frequently happens at border crossings). This, combined with the high ammonia levels, can cause death by suffocation.

In Europe, real space requirements exist and are enforced with dissuasive, proportionate sanctions.